<?php
// +----------------------------------------------------------------------
// | TOPThink [ WE CAN DO IT JUST THINK ]
// +----------------------------------------------------------------------
// | Copyright (c) 2010 http://topthink.com All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: 麦当苗儿 <zuojiazi@vip.qq.com> <http://www.zjzit.cn>
// +----------------------------------------------------------------------
// | GIF.class.php 2013-03-09
// +----------------------------------------------------------------------
namespace Think\Image\Driver;
class GIF{
    /**
     * GIF帧列表
     * @var array
     */
    private $frames = array();

    /**
     * 每帧等待时间列表
     * @var array
     */
    private $delays = array();

    /**
     * 构造方法，用于解码GIF图片
     * @param string $src GIF图片数据
     * @param string $mod 图片数据类型
     */
    public function __construct($src = null, $mod = 'url') {
        if(!is_null($src)){
            if('url' == $mod && is_file($src)){
                $src = file_get_contents($src);
            }
            /* 解码GIF图片 */
            try{
                $de = new GIFDecoder($src);
                $this->frames = $de->GIFGetFrames();
                $this->delays = $de->GIFGetDelays();
            } catch(\Exception $e){
                E("解码GIF图片出错");
            }
        }
    }

    /**
     * 设置或获取当前帧的数据
     * @param  string $stream 二进制数据流
     * @return boolean        获取到的数据
     */
    public function image($stream = null){
        if(is_null($stream)){
            $current = current($this->frames);
            return false === $current ? reset($this->frames) : $current;
        } else {
            $this->frames[key($this->frames)] = $stream;
        }
    }

    /**
     * 将当前帧移动到下一帧
     * @return string 当前帧数据
     */
    public function nextImage(){
        return next($this->frames);
    }

    /**
     * 编码并保存当前GIF图片
     * @param  string $gifname 图片名称
     */
    public function save($gifname){
        $gif = new GIFEncoder($this->frames, $this->delays, 0, 2, 0, 0, 0, 'bin');
        file_put_contents($gifname, $gif->GetAnimation());
    }

}


/*
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
::
::    GIFEncoder Version 2.0 by László Zsidi, http://gifs.hu
::
::    This class is a rewritten 'GifMerge.class.php' version.
::
::  Modification:
::   - Simplified and easy code,
::   - Ultra fast encoding,
::   - Built-in errors,
::   - Stable working
::
::
::    Updated at 2007. 02. 13. '00.05.AM'
::
::
::
::  Try on-line GIFBuilder Form demo based on GIFEncoder.
::
::  http://gifs.hu/phpclasses/demos/GifBuilder/
::
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
*/

Class GIFEncoder {
    private $GIF = "GIF89a";        /* GIF header 6 bytes    */
    private $VER = "GIFEncoder V2.05";    /* Encoder version        */

    private $BUF = Array ( );
    private $LOP =  0;
    private $DIS =  2;
    private $COL = -1;
    private $IMG = -1;

    private $ERR = Array (
        'ERR00'    =>    "Does not supported function for only one image!",
        'ERR01'    =>    "Source is not a GIF image!",
        'ERR02'    =>    "Unintelligible flag ",
        'ERR03'    =>    "Does not make animation from animated GIF source",
    );

    /*
    :::::::::::::::::::::::::::::::::::::::::::::::::::
    ::
    ::    GIFEncoder...
    ::
    */
    public function __construct($GIF_src, $GIF_dly, $GIF_lop, $GIF_dis,$GIF_red, $GIF_grn, $GIF_blu, $GIF_mod) {
        if ( ! is_array ( $GIF_src ) && ! is_array ( $GIF_dly ) ) {
            printf    ( "%s: %s", $this->VER, $this->ERR [ 'ERR00' ] );
            exit    ( 0 );
        }
        $this->LOP = ( $GIF_lop > -1 ) ? $GIF_lop : 0;
        $this->DIS = ( $GIF_dis > -1 ) ? ( ( $GIF_dis < 3 ) ? $GIF_dis : 3 ) : 2;
        $this->COL = ( $GIF_red > -1 && $GIF_grn > -1 && $GIF_blu > -1 ) ?
                        ( $GIF_red | ( $GIF_grn << 8 ) | ( $GIF_blu << 16 ) ) : -1;

        for ( $i = 0; $i < count ( $GIF_src ); $i++ ) {
            if ( strToLower ( $GIF_mod ) == "url" ) {
                $this->BUF [ ] = fread ( fopen ( $GIF_src [ $i ], "rb" ), filesize ( $GIF_src [ $i ] ) );
            }
            else if ( strToLower ( $GIF_mod ) == "bin" ) {
                $this->BUF [ ] = $GIF_src [ $i ];
            }
            else {
                printf    ( "%s: %s ( %s )!", $this->VER, $this->ERR [ 'ERR02' ], $GIF_mod );
                exit    ( 0 );
            }
            if ( substr ( $this->BUF [ $i ], 0, 6 ) != "GIF87a" && substr ( $this->BUF [ $i ], 0, 6 ) != "GIF89a" ) {
                printf    ( "%s: %d %s", $this->VER, $i, $this->ERR [ 'ERR01' ] );
                exit    ( 0 );
            }
            for ( $j = ( 13 + 3 * ( 2 << ( ord ( $this->BUF [ $i ] { 10 } ) & 0x07 ) ) ), $k = TRUE; $k; $j++ ) {
                switch ( $this->BUF [ $i ] { $j } ) {
                    case "!":
                        if ( ( substr ( $this->BUF [ $i ], ( $j + 3 ), 8 ) ) == "NETSCAPE" ) {
                            printf    ( "%s: %s ( %s source )!", $this->VER, $this->ERR [ 'ERR03' ], ( $i + 1 ) );
                            exit    ( 0 );
                        }
                        break;
                    case ";":
                        $k = FALSE;
                        break;
                }
            }
        }
        $this->GIFAddHeader ( );
        for ( $i = 0; $i < count ( $this->BUF ); $i++ ) {
            $this->GIFAddFrames ( $i, $GIF_dly [ $i ] );
        }
        $this->GIFAddFooter ( );
    }
    /*
    :::::::::::::::::::::::::::::::::::::::::::::::::::
    ::
    ::    GIFAddHeader...
    ::
    */
    private function GIFAddHeader ( ) {
        $cmap = 0;

        if ( ord ( $this->BUF [ 0 ] { 10 } ) & 0x80 ) {
            $cmap = 3 * ( 2 << ( ord ( $this->BUF [ 0 ] { 10 } ) & 0x07 ) );

            $this->GIF .= substr ( $this->BUF [ 0 ], 6, 7        );
            $this->GIF .= substr ( $this->BUF [ 0 ], 13, $cmap    );
            $this->GIF .= "!\377\13NETSCAPE2.0\3\1" . $this->GIFWord ( $this->LOP ) . "\0";
        }
    }
    /*
    :::::::::::::::::::::::::::::::::::::::::::::::::::
    ::
    ::    GIFAddFrames...
    ::
    */
    private function GIFAddFrames ( $i, $d ) {

        $Locals_str = 13 + 3 * ( 2 << ( ord ( $this->BUF [ $i ] { 10 } ) & 0x07 ) );

        $Locals_end = strlen ( $this->BUF [ $i ] ) - $Locals_str - 1;
        $Locals_tmp = substr ( $this->BUF [ $i ], $Locals_str, $Locals_end );

        $Global_len = 2 << ( ord ( $this->BUF [ 0  ] { 10 } ) & 0x07 );
        $Locals_len = 2 << ( ord ( $this->BUF [ $i ] { 10 } ) & 0x07 );

        $Global_rgb = substr ( $this->BUF [ 0  ], 13,
                            3 * ( 2 << ( ord ( $this->BUF [ 0  ] { 10 } ) & 0x07 ) ) );
        $Locals_rgb = substr ( $this->BUF [ $i ], 13,
                            3 * ( 2 << ( ord ( $this->BUF [ $i ] { 10 } ) & 0x07 ) ) );

        $Locals_ext = "!\xF9\x04" . chr ( ( $this->DIS << 2 ) + 0 ) .
                        chr ( ( $d >> 0 ) & 0xFF ) . chr ( ( $d >> 8 ) & 0xFF ) . "\x0\x0";

        if ( $this->COL > -1 && ord ( $this->BUF [ $i ] { 10 } ) & 0x80 ) {
            for ( $j = 0; $j < ( 2 << ( ord ( $this->BUF [ $i ] { 10 } ) & 0x07 ) ); $j++ ) {
                if    (
                        ord ( $Locals_rgb { 3 * $j + 0 } ) == ( ( $this->COL >> 16 ) & 0xFF ) &&
                        ord ( $Locals_rgb { 3 * $j + 1 } ) == ( ( $this->COL >>  8 ) & 0xFF ) &&
                        ord ( $Locals_rgb { 3 * $j + 2 } ) == ( ( $this->COL >>  0 ) & 0xFF )
                    ) {
                    $Locals_ext = "!\xF9\x04" . chr ( ( $this->DIS << 2 ) + 1 ) .
                                    chr ( ( $d >> 0 ) & 0xFF ) . chr ( ( $d >> 8 ) & 0xFF ) . chr ( $j ) . "\x0";
                    break;
                }
            }
        }
        switch ( $Locals_tmp { 0 } ) {
            case "!":
                $Locals_img = substr ( $Locals_tmp, 8, 10 );
                $Locals_tmp = substr ( $Locals_tmp, 18, strlen ( $Locals_tmp ) - 18 );
                break;
            case ",":
                $Locals_img = substr ( $Locals_tmp, 0, 10 );
                $Locals_tmp = substr ( $Locals_tmp, 10, strlen ( $Locals_tmp ) - 10 );
                break;
        }
        if ( ord ( $this->BUF [ $i ] { 10 } ) & 0x80 && $this->IMG > -1 ) {
            if ( $Global_len == $Locals_len ) {
                if ( $this->GIFBlockCompare ( $Global_rgb, $Locals_rgb, $Global_len ) ) {
                    $this->GIF .= ( $Locals_ext . $Locals_img . $Locals_tmp );
                }
                else {
                    $byte  = ord ( $Locals_img { 9 } );
                    $byte |= 0x80;
                    $byte &= 0xF8;
                    $byte |= ( ord ( $this->BUF [ 0 ] { 10 } ) & 0x07 );
                    $Locals_img { 9 } = chr ( $byte );
                    $this->GIF .= ( $Locals_ext . $Locals_img . $Locals_rgb . $Locals_tmp );
                }
            }
            else {
                $byte  = ord ( $Locals_img { 9 } );
                $byte |= 0x80;
                $byte &= 0xF8;
                $byte |= ( ord ( $this->BUF [ $i ] { 10 } ) & 0x07 );
                $Locals_img { 9 } = chr ( $byte );
                $this->GIF .= ( $Locals_ext . $Locals_img . $Locals_rgb . $Locals_tmp );
            }
        }
        else {
            $this->GIF .= ( $Locals_ext . $Locals_img . $Locals_tmp );
        }
        $this->IMG  = 1;
    }
    /*
    :::::::::::::::::::::::::::::::::::::::::::::::::::
    ::
    ::    GIFAddFooter...
    ::
    */
    private function GIFAddFooter ( ) {
        $this->GIF .= ";";
    }
    /*
    :::::::::::::::::::::::::::::::::::::::::::::::::::
    ::
    ::    GIFBlockCompare...
    ::
    */
    private function GIFBlockCompare ( $GlobalBlock, $LocalBlock, $Len ) {

        for ( $i = 0; $i < $Len; $i++ ) {
            if    (
                    $GlobalBlock { 3 * $i + 0 } != $LocalBlock { 3 * $i + 0 } ||
                    $GlobalBlock { 3 * $i + 1 } != $LocalBlock { 3 * $i + 1 } ||
                    $GlobalBlock { 3 * $i + 2 } != $LocalBlock { 3 * $i + 2 }
                ) {
                    return ( 0 );
            }
        }

        return ( 1 );
    }
    /*
    :::::::::::::::::::::::::::::::::::::::::::::::::::
    ::
    ::    GIFWord...
    ::
    */
    private function GIFWord ( $int ) {

        return ( chr ( $int & 0xFF ) . chr ( ( $int >> 8 ) & 0xFF ) );
    }
    /*
    :::::::::::::::::::::::::::::::::::::::::::::::::::
    ::
    ::    GetAnimation...
    ::
    */
    public function GetAnimation ( ) {
        return ( $this->GIF );
    }
}


/*
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
::
::    GIFDecoder Version 2.0 by László Zsidi, http://gifs.hu
::
::    Created at 2007. 02. 01. '07.47.AM'
::
::
::
::
::  Try on-line GIFBuilder Form demo based on GIFDecoder.
::
::  http://gifs.hu/phpclasses/demos/GifBuilder/
::
:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
*/

Class GIFDecoder {
    private $GIF_buffer = Array ( );
    private $GIF_arrays = Array ( );
    private $GIF_delays = Array ( );
    private $GIF_stream = "";
    private $GIF_string = "";
    private $GIF_bfseek =  0;

    private $GIF_screen = Array ( );
    private $GIF_global = Array ( );
    private $GIF_sorted;
    private $GIF_colorS;
    private $GIF_colorC;
    private $GIF_colorF;

    /*
    :::::::::::::::::::::::::::::::::::::::::::::::::::
    ::
    ::    GIFDecoder ( $GIF_pointer )
    ::
    */
    public function __construct ( $GIF_pointer ) {
        $this->GIF_stream = $GIF_pointer;

        $this->GIFGetByte ( 6 );    // GIF89a
        $this->GIFGetByte ( 7 );    // Logical Screen Descriptor

        $this->GIF_screen = $this->GIF_buffer;
        $this->GIF_colorF = $this->GIF_buffer [ 4 ] & 0x80 ? 1 : 0;
        $this->GIF_sorted = $this->GIF_buffer [ 4 ] & 0x08 ? 1 : 0;
        $this->GIF_colorC = $this->GIF_buffer [ 4 ] & 0x07;
        $this->GIF_colorS = 2 << $this->GIF_colorC;

        if ( $this->GIF_colorF == 1 ) {
            $this->GIFGetByte ( 3 * $this->GIF_colorS );
            $this->GIF_global = $this->GIF_buffer;
        }
        /*
         *
         *  05.06.2007.
         *  Made a little modification
         *
         *
         -    for ( $cycle = 1; $cycle; ) {
         +        if ( GIFDecoder::GIFGetByte ( 1 ) ) {
         -            switch ( $this->GIF_buffer [ 0 ] ) {
         -                case 0x21:
         -                    GIFDecoder::GIFReadExtensions ( );
         -                    break;
         -                case 0x2C:
         -                    GIFDecoder::GIFReadDescriptor ( );
         -                    break;
         -                case 0x3B:
         -                    $cycle = 0;
         -                    break;
         -              }
         -        }
         +        else {
         +            $cycle = 0;
         +        }
         -    }
        */
        for ( $cycle = 1; $cycle; ) {
            if ( $this->GIFGetByte ( 1 ) ) {
                switch ( $this->GIF_buffer [ 0 ] ) {
                    case 0x21:
                        $this->GIFReadExtensions ( );
                        break;
                    case 0x2C:
                        $this->GIFReadDescriptor ( );
                        break;
                    case 0x3B:
                        $cycle = 0;
                        break;
                }
            }
            else {
                $cycle = 0;
            }
        }
    }
    /*
    :::::::::::::::::::::::::::::::::::::::::::::::::::
    ::
    ::    GIFReadExtension ( )
    ::
    */
    private function GIFReadExtensions ( ) {
        $this->GIFGetByte ( 1 );
        for ( ; ; ) {
            $this->GIFGetByte ( 1 );
            if ( ( $u = $this->GIF_buffer [ 0 ] ) == 0x00 ) {
                break;
            }
            $this->GIFGetByte ( $u );
            /*
             * 07.05.2007.
             * Implemented a new line for a new function
             * to determine the originaly delays between
             * frames.
             *
             */
            if ( $u == 4 ) {
                $this->GIF_delays [ ] = ( $this->GIF_buffer [ 1 ] | $this->GIF_buffer [ 2 ] << 8 );
            }
        }
    }
    /*
    :::::::::::::::::::::::::::::::::::::::::::::::::::
    ::
    ::    GIFReadExtension ( )
    ::
    */
    private function GIFReadDescriptor ( ) {
        $GIF_screen    = Array ( );

        $this->GIFGetByte ( 9 );
        $GIF_screen = $this->GIF_buffer;
        $GIF_colorF = $this->GIF_buffer [ 8 ] & 0x80 ? 1 : 0;
        if ( $GIF_colorF ) {
            $GIF_code = $this->GIF_buffer [ 8 ] & 0x07;
            $GIF_sort = $this->GIF_buffer [ 8 ] & 0x20 ? 1 : 0;
        }
        else {
            $GIF_code = $this->GIF_colorC;
            $GIF_sort = $this->GIF_sorted;
        }
        $GIF_size = 2 << $GIF_code;
        $this->GIF_screen [ 4 ] &= 0x70;
        $this->GIF_screen [ 4 ] |= 0x80;
        $this->GIF_screen [ 4 ] |= $GIF_code;
        if ( $GIF_sort ) {
            $this->GIF_screen [ 4 ] |= 0x08;
        }
        $this->GIF_string = "GIF87a";
        $this->GIFPutByte ( $this->GIF_screen );
        if ( $GIF_colorF == 1 ) {
            $this->GIFGetByte ( 3 * $GIF_size );
            $this->GIFPutByte ( $this->GIF_buffer );
        }
        else {
            $this->GIFPutByte ( $this->GIF_global );
        }
        $this->GIF_string .= chr ( 0x2C );
        $GIF_screen [ 8 ] &= 0x40;
        $this->GIFPutByte ( $GIF_screen );
        $this->GIFGetByte ( 1 );
        $this->GIFPutByte ( $this->GIF_buffer );
        for ( ; ; ) {
            $this->GIFGetByte ( 1 );
            $this->GIFPutByte ( $this->GIF_buffer );
            if ( ( $u = $this->GIF_buffer [ 0 ] ) == 0x00 ) {
                break;
            }
            $this->GIFGetByte ( $u );
            $this->GIFPutByte ( $this->GIF_buffer );
        }
        $this->GIF_string .= chr ( 0x3B );
        /*
           Add frames into $GIF_stream array...
        */
        $this->GIF_arrays [ ] = $this->GIF_string;
    }
    /*
    :::::::::::::::::::::::::::::::::::::::::::::::::::
    ::
    ::    GIFGetByte ( $len )
    ::
    */

    /*
     *
     *  05.06.2007.
     *  Made a little modification
     *
     *
     -    function GIFGetByte ( $len ) {
     -        $this->GIF_buffer = Array ( );
     -
     -        for ( $i = 0; $i < $len; $i++ ) {
     +            if ( $this->GIF_bfseek > strlen ( $this->GIF_stream ) ) {
     +                return 0;
     +            }
     -            $this->GIF_buffer [ ] = ord ( $this->GIF_stream { $this->GIF_bfseek++ } );
     -        }
     +        return 1;
     -    }
     */
    private function GIFGetByte ( $len ) {
        $this->GIF_buffer = Array ( );

        for ( $i = 0; $i < $len; $i++ ) {
            if ( $this->GIF_bfseek > strlen ( $this->GIF_stream ) ) {
                return 0;
            }
            $this->GIF_buffer [ ] = ord ( $this->GIF_stream { $this->GIF_bfseek++ } );
        }
        return 1;
    }
    /*
    :::::::::::::::::::::::::::::::::::::::::::::::::::
    ::
    ::    GIFPutByte ( $bytes )
    ::
    */
    private function GIFPutByte ( $bytes ) {
        for ( $i = 0; $i < count ( $bytes ); $i++ ) {
            $this->GIF_string .= chr ( $bytes [ $i ] );
        }
    }
    /*
    :::::::::::::::::::::::::::::::::::::::::::::::::::
    ::
    ::    PUBLIC FUNCTIONS
    ::
    ::
    ::    GIFGetFrames ( )
    ::
    */
    public function GIFGetFrames ( ) {
        return ( $this->GIF_arrays );
    }
    /*
    :::::::::::::::::::::::::::::::::::::::::::::::::::
    ::
    ::    GIFGetDelays ( )
    ::
    */
    public function GIFGetDelays ( ) {
        return ( $this->GIF_delays );
    }
}
